Iterate through elements of a LinkedList using a ListIterator in Java

A ListIterator can be used to traverse the elements in the forward direction as well as the reverse direction in a LinkedList.

The method hasNext( ) in ListIterator returns true if there are more elements in the LinkedList while traversing in the forward direction and false otherwise. The method next( ) returns the next element in the LinkedList and advances the cursor position.

The method hasPrevious( ) in ListIterator returns true if there are more elements in the LinkedList while traversing in the reverse direction and false otherwise. The method previous( ) returns the previous element in the LinkedList and reduces the cursor position backward.

A program that demonstrates this is given as follows.

Example

 Live Demo

import java.util.ListIterator; import java.util.LinkedList; public class Demo {    public static void main(String[] args) {       LinkedList<String> l = new LinkedList<String>();       l.add("Andy");       l.add("Sara");       l.add("James");       l.add("Betty");       l.add("Bruce");       ListIterator li = l.listIterator();       System.out.println("The LinkedList elements in the forward direction are: ");       while (li.hasNext()) {          System.out.println(li.next());       }       System.out.println("\nThe LinkedList elements in the reverse direction are: ");       while (li.hasPrevious()) {          System.out.println(li.previous());       }    } }

Output

The output of the above program is as follows −

The LinkedList elements in the forward direction are: Andy Sara James Betty Bruce The LinkedList elements in the reverse direction are: Bruce Betty James Sara Andy

Now let us understand the above program.

The LinkedList is created and  LinkedList.add() is used to add the elements to the  LinkedList. A code snippet which demonstrates this is as follows

LinkedList<String> l = new LinkedList<String>(); l.add("Andy"); l.add("Sara"); l.add("James"); l.add("Betty"); l.add("Bruce");

Then the ListIterator interface is used to display the LinkedList elements in the forward and reverse direction. A code snippet which demonstrates this is as follows

ListIterator li = l.listIterator(); System.out.println("The LinkedList elements in the forward direction are: "); while (li.hasNext()) {    System.out.println(li.next()); } System.out.println("\nThe LinkedList elements in the reverse direction are: "); while (li.hasPrevious()) {    System.out.println(li.previous()); }